Spiral perm rods have been available for some time, but current designs are awkward to use, easily loosen up in the hair to produce poor quality curls, and slow down the operator considerably because of their inferior design. Consequently, there is a general trend away from spiral rods, even though a good-looking, spiral curl is quite popular and highly sought after. As a consequence, in order to save time, may operators use so-called straight perm rods which are actually intended to be used for curls having convolutions which are simply wrapped up on top of one another in multiple layers, rather than stretched out in a single-layered, helical pattern. While straight rods are usable for producing spiral curls, they, too, are not ideal and tend to produce a lower quality end result.